Attachment N o F.2 EMISSIONS MONITORING AND SAMPLING POINTS

Transcription

1 Attachment N o F.2 EMISSIONS MONITORING AND SAMPLING POINTS Lagan Cement Ltd. IPPC Licence Application

2 Attachment N o F.2 EMISSIONS MONITORING AND SAMPLING POINTS Air Contents F.2.0 Air Emissions.3 Water F.2.1 Introduction... 4 F.2.2 Major emission point (SW1) OS E, N... 4 F.2.3 Minor emission point (SW2) OS E, N... 7 Attachment N o F.2 Page 2 of 7

3 AIR F.2.0 Air Emissions All sampling points will remain as currently in place and as specified in Schedule B(1) of IPPC Licence Register No P There will be no additional emission points as a result of this proposal. The main potential impacts on air quality associated with the existing activities at the site relate to emissions of dust and combustion gases such as SO 2 (sulphur dioxide), NO 2 (nitrogen dioxide) and CO (carbon monoxide). These emissions are currently being monitored as part of the ongoing monitoring programme at the site. In addition, HCl, HF, Heavy Metals and Dioxins and Furans are also measured in the emission stream from the main stack as part of the monitoring requirements. The operation of the plant using the proposed alternative fuels will not lead to the discharge of any additional emissions from the main stack into the atmosphere. All current emissions monitoring will remain in place as required by IPPC Licence Register No P and as discussed in detail in Section 9 of the Planning and Environmental Report. Attachment N o F.2 Page 3 of 7

4 WATER F.2.1 Introduction The main surface water resources in the vicinity of the site are the Kinnegad and Castlejordan Rivers. The Lagan Cement Ltd site lies entirely within the catchment of the Kinnegad River, which forms the northern boundary of part of the site, just north of the shale quarry. The source of the Kinnegad River is located west of the site and the surface water divide between the catchments of the Kinnegad and Castlejordan Rivers lies to the south of the site. The existing cement works and quarry facility is licenced by the EPA and a number of conditions in the IPPC Licence define monitoring requirements for the Operational Phase of the development. The existing ongoing monitoring programme was implemented for the duration of the construction phase of the project and is continuing since cement production commenced. The proposed addition of two new alternative fuels to the fuel list at the facility will also be regulated under the terms of the IPPC Licence. There will be no impacts on the surface water and groundwater at the site as a result of this proposal and there are no proposed changes to the surface water and groundwater management regime at the site. This section outlines the existing operational drainage system and control systems to handle the water discharge at the emission points SW1 and SW2. F.2.2 Major emission point (SW1) OS E, N The major emission point at SW1 comprises all pumped groundwater from the limestone and shale quarry and surface run-off, including treated effluent from the works pond and runoff from the surrounding areas. The water is discharged in the Kinnegad River via an oil trap and the settlement lagoons. The details of abatement/treatments systems, quarry sumps and ongoing monitoring programme are presented below. Surface Water Collection and Handling There are three main sumps used for water management at the site. The terrace sump, which manages surface water run-off in the plant area, the shale quarry sump and the limestone quarry sump which manage groundwater pumped from the two quarries. A flow chart for the storm water and groundwater management at the facility is presented in Appendix I of this report. The terrace sump is located at the northern end of the raw materials reception and handling compound and has a maximum discharge rate of 200m 3 /hr which is controlled by means of a float switch. The 35 x 40 x 3m sump is formed at a low level to avoid two-stage pumping and water from here is pumped via two 160mm pipes to an inlet chamber from where it is gravity fed into the balancing pond. Water is pumped on an as-required basis using a level controlled submersible pump capable of handling inflows in excess of Attachment N o F.2 Page 4 of 7

5 700l/sec. The sole function of the terrace sump is to pump stormwater from the surface water drains in the main plant yard area and therefore this sump only functions during rainfall. Waters from the balancing pond are gravity fed into the pre-settlement lagoon from where they are fed onto the main settlement lagoon again under gravity. The limestone quarry sump has a maximum discharge rate of 138m 3 /hr, which is controlled by means of a float switch. Water is pumped from the limestone quarry sump on an intermittent basis as required. The limestone quarry sump discharge is pumped to the inlet chamber from where it is gravity fed to the balancing pond. From here it is directed to the pre-settlement lagoon and then onto the settlement lagoon. The shale quarry sump has a maximum discharge rate of 45m 3 /hr and is controlled by means of a float switch. Water is pumped from the shale quarry into a purpose built drain and then flows by gravity into the pre-settlement lagoon and on into the settlement lagoon. Water may be directed to the balancing pond from the shale quarry sump if flow rates from the balancing pond to the settlement lagoons would exceed those which can permit settlement of suspended solids in the settlement lagoons. Surface Water Treatment The balancing pond and the settlement lagoons are the main features of the surface water management system at the site. Balancing Pond The balancing pond receives all water pumped from the terrace sump and the limestone quarry sump and can receive water from the shale quarry sump if and when required. The balancing pond measures 170 x 110 x 4m deep and is designed to accept excess run-off from storm conditions up to a 20 year return storm. The volume of the balancing pond is approximately 35,000m 3 and the top water level is 85.5mAOD and the invert of the discharge pipe is at 82.25mAOD. To be able to function at times of high rainfall, it is necessary for the pond water level generally to be low. The discharge from the balancing pond is regulated by a 52mm diameter throttle plate attached to the outflow pipe. Oil traps are installed to intercept any potential on-site spillage of hydrocarbons. The water from the balancing pond flows under gravity to the pre settlement lagoon in a 225mm drainpipe. Water from the balancing pond flows at a rate not exceeding 109m³/hr (for the 20 year storm) and at a mean discharge rate of 75m³/hr (for the same storm). This ensures that excess water during storms can be regulated in discharge to the settlement lagoons whilst these lagoons are still receiving some pumped ground water. Settlement Lagoons Attachment N o F.2 Page 5 of 7

6 The settlement lagoons are located just north of the shale quarry and discharge into the Kinnegad River at the emission point SW1. The volume of the presettlement lagoon and the settlement lagoon is 35,000m 3 and 70,000m 3 respectively. The settlement lagoons receive water pumped directly from the sumps of the two quarries and from the balancing pond. The maximum permitted discharge rate from the settlement lagoons to the Kinnegad River is 260m³/hr or 6150m³/d (71 l/s). The design residence time in the settlement lagoons is 28 hrs. The final discharge to SW1 is via a pipe from the overflow weir. An oil interceptor is installed to remove oils and hydrocarbons from all inflow. The minimum daily discharge to the Kinnegad River will be solely that from groundwater pumping during periods of drought viz 3,520m 3 /d (after 38 years). The routings of surface water run-off either via the works sumps, balancing pond and settlement lagoons or via the quarry sumps and the settlement lagoons are such that it is most unlikely that significant increases in discharge will arrive at SW1 until 48 hours after a heavy end-of-drought rainfall. After prolonged drought it is likely that the quarry sumps receiving surface water run-off would be low having been used to provide water for dust suppression. Hence, increased discharges into the Kinnegad River, following heavy rainfall, should correspond to a parallel increase in river flow. The maximum controlled rate of discharge of both surface water and pumped groundwater is 6150m³/d. The mean surface water and pumped groundwater flow will be 5,040m3/d (after 38 years). Mean discharges will normally occur during normal periods of rainfall and not during droughts. Flow from the settlement lagoons to the Kinnegad River (emission point SW1) are continuously monitored and when this exceeds 256m³/hr water from one or both of the quarries, is switched automatically to feed into the balancing pond. For storms beyond the 20 year return period water would be allowed to rise in one or both of the quarries. Therefore, the outlet from the settlement lagoon acts as a hydrobrake, designed to flood at the balancing pond and the settlement lagoons in the event that storm flow and pump rates from the quarries exceed the discharge limit. Surface Water Monitoring The water at the emission point SW1 is sampled with a flow proportional sampler with 24-hour composite samples being collected. An automatic ph sensor is also installed at the emission point. The ph of the discharge water should always lie in the range 6 to 9. Daily samples are also tested for suspended solids. Discharge BOD is recorded weekly. Mineral Oil presence is checked visually on a daily basis and oils, fats and greases are recorded monthly as required by the terms and conditions of the IPPC Licence. If (as is considered unlikely) dirty water discharges above the limit of 35mg/l, an automatic diversion system for flow through the attenuation pond will be installed. This will be triggered by means of a calibrated photocell control. Attachment N o F.2 Page 6 of 7

7 F.2.3 Minor emission point (SW2) OS E, N The minor emission point at SW2 comprises surface water runoff from fields and permanent seeded/planted screening banks from the southwestern part of the site. Runoff from the screening banks is collected in perimeter ditches and routed to a combined silt/oil trap facility. A controlled flow of 7l/s discharges into the westerly flowing ditch via the minor emission SW2. Storm attenuation area The area lying east of the silt and oil interceptor is allowed to flood to a maximum depth of 0.8m over a maximum area of 88 x 176m in order to attenuate storm flow. Bunding was installed around the perimeter of the plant area as a flood prevention measure. The discharge at SW2 will not exceed 600m³/d and will be c 100m³/d for mean surface water run-off. Operational and monitoring arrangements The surface water emitted at SW2 does not comprise any process effluent or runoff from working or quarry areas. The emitted water only comprises runoff generated from greenfield and woodland. No abatement /control systems is therefore required for this emission point. However, as a matter of precaution a silt/oil trap was installed upstream from the emission point. The discharge at this emission point is usually at a very slow rate with a near static water at many of the ditches connected to the outflow for the site. Attachment N o F.2 Page 7 of 7